From 1998 to 2006, Wilmer Valderrama played one of the most hilarious characters on the show. In case you need a quick refresher, he was part of the legendary group of friends who used to hang out at "Eric Forman's" (Topher Grace) place.
That 70's Show - This is what Wilmer Valderrama's character "Fez" means
"Fez" joins the group of six teenagers from the very first season, and although his native country is never revealed on the show, he is assumed to be of Latino or Hispanic descent. As simple as it sounds, "Fez" is short for "Foreign Exchange Student," some sort of nickname his friends choose after learning they are not able to pronounce his actual name, which always remained a mystery.
Wilmer Valderrama certainly did a pretty good job portraying "Fez," especially by depicting - with a very special sense of humour - the cultural struggles some foreigners might experience after moving to the United States.